THE QD-ALGORITHM AS A METHOD FOR FINDING THE ROOTS OF A POLYNOMIAL EQUATION WHEN ALL ROOTS ARE POSITIVE.

Abstract

The Quotient-Difference (QD)-scheme, symmetric functions and some results from the theory of Hankel determinants are treated. Some well known relations expressing the elements of the QD-scheme by means of the Hankel determinants are presented. The question of convergence of the columns of the QD-scheme is treated. An exact expression for q sub n(k) is developed for the case of different roots. It is proved that the columns of the QD-scheme will converge not only in the well known case of different roots, but in all cases where the roots are positive. A detailed examination of the convergence to the smallest root is presented. An exact expression for q sub n(N) is developed. This expression, is correct in all cases of multiple positive roots. It is shown that the progressive form of the QD-algorithm is only 'mildly unstable'. Finally, some ALGOL programs and some results obtained by means of these, are given.

Document Details

Document Type
Technical Report
Publication Date
Jun 08, 1964
Accession Number
AD0604012

Entities

People

  • Chr. Andersen

Organizations

  • Stanford University

Tags

DTIC Thesaurus Topics

  • Algorithms
  • Convergence
  • Equations
  • Mathematics

Fields of Study

  • Mathematics

Readers

  • Approximation Theory.
  • Calculus or Mathematical Analysis